The present invention relates to a motor vehicle steering column, and more particularly to such a steering column in which the bearing section of a jacket tube, as viewed in the transverse direction, is slidably arranged on the console and the jacket tube is connected to a body part having a high impedance.
In a known steering column as shown in DE-PS 27 51 068, a jacket tube is firmly connected by fastening screws with the console disposed above it. A bearing section of the jacket tube, in this arrangement, is braced by the fastening screw against the lateral webs of the console or against washers. By way of this axial bracing in the transverse direction of the vehicle, the vibrations of the forward structure of the motor vehicle are transmitted to the steering column by the console so that, at certain critical speed ranges and particularly in the case of a body of a convertible, a shaking of the steering wheel will occur. Critical speed ranges are those at which forms of natural vibrations of the vehicle are caused, for example, by a wheel imbalance or by a rough road.
In order to reduce the shaking of the steering wheel, it has been suggested in U.S. Pat. No. 4,671,536 to support the bracket additionally by a support structure at the two exterior A-columns and at the center console. A first element of the support structure, in this situation, connects the two laterally exterior A-columns, whereas a second element, on the one side, is connected to the transmission tunnel and, on the other side to the adjacent A-column. Since, however, the two A-columns exercise relatively high vibrations in the transverse direction of the vehicle i.e. low impedance, also in this arrangement, the vibrations are transmitted by way of the support structure to the steering console into the steering column so that only a slight improvement of the shaking of the steering wheel can be achieved with this support structure.
It is an object of the present invention to take such measures on the body or on the steering column of the motor vehicle that a significant improvement of the shaking of the steering wheel is achieved also at critical speed ranges and in the case of a body of a convertible.
According to the present invention, this object has been achieved by slidably arranging the bearing section of the jacket tube, as viewed in the transverse direction, on the console. The jacket tube is connected to a body part having a high impedance via a supporting element.
Principal advantages achieved by the present invention are that, by means of the displaceable bearing of the steering column on the console as viewed in the transverse direction, an uncoupling of vibrations is effected between the steering column and the forward structure of the motor vehicle, whereby the vibrations of the forward structure of the motor vehicle are not transmitted to the steering column or the jacket tube by way of the console. In the transverse direction, the jacket tube or the steering column is connected by way of the supporting element only with a low-vibration or high impedance body part, whereby the shaking of the steering wheel is reduced significantly. Preferably, the supporting element is connected with a bearing section of the jacket tube and the transmission tunnel. By the uncoupling of the steering console and the jacket tube, the steering console can move in the transverse direction relative to the jacket tube. The fixing of the steering column in the longitudinal and the vertical direction takes place by the fastening screws of the console. However, the vibrations in these two directions are negligibly low.